Pictures under the Creative Commons Zero (CC0) license are free for personal and even commercial usage.
- Attribution is not required; however, we do encourage users to give credit to the photographer if possible. Obviously, the photographer has donated the image for free usage so it is always nice to reciprocate with a credit if you can do so. This is not obligatory though, and you can use the images without giving a credit, if you so desire.
- One key restriction is that identifiable people may not appear in a bad light or in a way that they may find offensive (unless of course you actually have written permission from them for this usage).
- You should also not use images with identifiable brand names, property, logos, copyrighted or trade-marked material for commercial advertising. Editorial usage is generally okay as long as it is for news worthy purposes.